SUMMARY: Powerdrive

From: Mark S. Anderson (
Date: Fri Jul 23 1993 - 20:46:09 CDT

I am re-sending this message to the list with the subject line correct
to include the word SUMMARY so that ti will be archived automatically.
Please excuse the redundancy.

----- Begin Included Message -----

>From Wed Jul 21 23:46:45 1993
Organization: The MITRE Corp.
Precedence: bulk
Date: Wed, 21 Jul 93 11:44:21 EST
From: (Larry Freeman)
Reply-To: (Larry Freeman)
Subject: Powerdrive Responses
Status: RO

Many thanks for the feedback to my posting:

> I recently got some info from a company called Revolution Technologies.
> They have a software package called powerdrive that does automatic file
> compression/decompression. Since my disks always seem to run at
> 95%-100% (no matter how hard I try), this package seems to be worth the
> $100 cost.
> powerdrive got a pretty good write up in Sun World, but has anyone used it
> in the "Real World"?

I got 10 responses - here's the score:

                3 - Love it - using it despite minor bugs/features
                3 - Like it - using it despite minor bugs/features
                3 - Tried it - didn't like it
                1 - Competitive Product Info

Powerdrive is sold by Revolution Technologies. Their number is 508-650-1490,

I also got information on a competitive product, 'Crusher' from magma - (Maybe someone else wants to do a review of this product).

Based on the comments, I will be trying out Powerdrive on my network.

Starting with the people who loved it, it seems that as long as you tune the
setup, Powerdrive is a very good product. This was best explained by:


I've run PowerDrive for several months on a couple of
machines. It's GREAT provided

(a) You use it on appropriate directories (as I'll
describe below).

My main application for PowerDrive is against large
online source archives which are only accessed
infrequently and in small pieces. It's also great for
compressing the 80% of the junk on your /usr volume that
you never touch.
PowerDrive would NOT be appropriate for something like an
NNTP server, with zillions of small, frequently-changing,
frequently-referenced files.

(b) You don't do something dumb like tell it to compress
files that the system needs before the PowerDrive driver
is running. (The defaults they provide should be OK.)
--------------------------------------------------------------------------- added:

For $100, it's a steal, compared to buying more disks. Think about
how disk compression has become positively STANDARD on DOS machines.
And from

We've been running powerdrive since May with no problems. In fact, I had
not even thought about it for some time until your request!

The people not so vehement, but still using Powerdrive:
-------------------------------------------------------------------------- had these 'quirks':

1) The Sun OpenWindow filemgr application has a feature (or is it a
bug :{) ) where by it opens every file in the current directory to
determine it's type. This forces an immediate uncompress on all the
files in that dir. This can be hazardous if you have a data file
directory, for instance, which, when uncompressed, blows the doors off
the file system.

(He spoke to the Powerdrive people, has installed patch #'s 100462-14,
 100452-28, & 100524-06. Still havind problems, though).

2) I had to modify my script to disable the powerdrive utility during
the dump so that the files would not uncompress again automatically
when touched.

I tried it in my home machine, and it worked pretty well--allowed me to fit
OW 3.0 on my disks--except for a weird problem in which periodically, every
command you try to run in a shell window gets "too many open files" or the

Revolution Technologies has not informed me of any fix for this problem. I'm
still using it, since flawed though it is, I can't fit SunOS + OW 3.0 into
two Quantum 105s without it...

Here are some comments from the people who were not happy with Powerdrive:

Also, after I told them that I removed the software
(because there was a POSSIBILITY that it could have crashed my 630mp
server) they never did call back for a follow up. If I were the vendor,
I wold want to know damn quick if my software had caused a crash.

Overall, I was not impressed.....

I tried out PowerDrive for a while. I ended up having several problems
and decided not to continue using it.

If a file meets
the criteria for compression (x many hours or days since it was touched)
it must open that file and read a header from the file to decide if it
is already compressed, if so it leaves it, if not it compresses it. So
you can see that with a file system of 50,000+ files you will be
waiting a LONG time for it to complete it's compression pass.

Thanks To These And Other Future sun-Respondents: (Ted Whitley) (Dan Zambon)
Mike Raffety <> (Ken Stoddart)
Rodger R. Getz <>
"Dan Franklin" <>
ed@magma.COM (Ed Romascan)
aga@Comtech.COM (Alan G. Arndt) (Michael Sullivan) (Alan H. Mintz)

----- End Included Message -----

Mark Anderson
The MITRE Corporation
7525 Colshire Drive, MS W747 voice: (703) 883-6439
McLean, VA 22102 FAX: (703) 883-1905

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